Scientific Principle
The fundamental limits on what can be known or predicted. Heisenberg's uncertainty principle makes this a property of physical reality, not merely of measurement. Statistical mechanics and information theory describe how to reason carefully within those limits.
Other principles
In 2019, we photographed one black hole. We know millions more exist in the Milky Way alone. That gap is not a problem of knowledge — it is a gap in detection technology, and indirect evidence is not a lesser form of evidence.
Black holes are among the best-supported objects in physics — and among the strangest. Ole Eggers Bjælde explains what they actually are, how time behaves near one, and what the next generation of research will require to resolve what remains unknown.
Astrobiology is criticised for being Earth-centric. That criticism misunderstands the epistemics. You cannot search for something you cannot characterise — and Earth is the only example of life we have.
The search for extraterrestrial life starts with Earth — not because scientists lack imagination, but because Earth is the only confirmed example of life that exists. Kai Finster explains why using Earth's biochemistry as a template is not anthropocentric bias. It is the only scientifically defensible starting point.